165625510628561 has 2 divisors, whose sum is σ = 165625510628562. Its totient is φ = 165625510628560.

The previous prime is 165625510628527. The next prime is 165625510628581. The reversal of 165625510628561 is 165826015526561.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110874982218961 + 54750528409600 = 10529719^2 + 7399360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165625510628561 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165625510628561.

It is not a weakly prime, because it can be changed into another prime (165625510628581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82812755314280 + 82812755314281.

It is an arithmetic number, because the mean of its divisors is an integer number (82812755314281).

Almost surely, 2^{165625510628561} is an apocalyptic number.

It is an amenable number.

165625510628561 is a deficient number, since it is larger than the sum of its proper divisors (1).

165625510628561 is an equidigital number, since it uses as much as digits as its factorization.

165625510628561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920000, while the sum is 59.

The spelling of 165625510628561 in words is "one hundred sixty-five trillion, six hundred twenty-five billion, five hundred ten million, six hundred twenty-eight thousand, five hundred sixty-one".